A 56-page notebook manuscript by Alan Turing, the English mathematician considered to be the father of modern computer science, was sold at auction Monday for US$1.025 million.

The manuscript is almost certainly the most extensive by Turing, in his own hand, in existence, experts at Bonhams auction house said. Turing apparently wrote in the notebook in 1942 when he was working in Bletchley Park, England, trying to break German military code.

The bidding took place at Bonhams on Madison Avenue in New York, with about 50 bidders present in the auction room and lines open for bids coming in by phone and Internet. The winning bid was from a private collector who did not wish to be identified.

Turing’s story became more widely known last year with the release of the Oscar-nominated film, “The Imitation Game,” which focused on his role in breaking the code generated by the German Enigma machine. His work as the leader of the team charged with breaking the code is thought to have shortened World War II by several years, saving countless lives.

An original, fully functional code-generating Enigma machine, made in Berlin in 1944, was also auctioned off Monday, for a winning bid of $269,000. The winning bidder was not immediately available for comment.

The machine scrambles plain text and produces cipher text messages, which were then transmitted by Morse code for the German military to coordinate their actions.

The notebook sold Monday contains notes on the foundations of mathematical notation and computer science.

“It gives us insight into how Alan Turing tackles problems. Sadly it shows us what he never got to finish,” said Cassandra Hatton, senior specialist at Bonhams.

Though the notebook is filled with the math notation, there are also comments that give glimpses into his personality and passion. Alongside one set of equations, for example, he commented, “hateful!”

Among Turing’s unfinished projects was the development of what Hatton called a universal computing language. In the manuscript, Turing was primarily taking notes on mathematical notation.

“Primarly he’s looking at notation and he’s concerned with the precision of this notation,” Hatton said. “He’s studying the work of many other people who were working on universal languages and I think it’s because Turing himself was thinking about working on a universal language. At the age of 24 just a few years prior to this he had invented the universal computing machine so the natural next step was to think about a universal language for this machine.”

Turing left all his papers, including the notebook, to his friend and fellow mathematician Robin Gandy. Gandy turned Turing’s dream journals over to a psychiatrist, who burned them, and gave Turing’s scientific papers to Kings College. Gandy however kept this one notebook because in the middle of it, in some blank pages, he wrote his own private journal.

Gandy died in 1995, and the current owner of the manuscript was not disclosed by the auction house. Some of the proceeds of the auction are to be donated to charity.

Turing’s accomplishments, in computing and other fields, were many. His 1936 paper describing what would become known as the Turing Machine and his work on what was called the Automatic Computing Engine (ACE) pioneered concepts of programmable computers and stored memory. He also developed ideas for non-linear biological theory.

Turing’s life ended tragically. He faced criminal charges for homosexual acts, which were illegal at the time in the U.K. Upon his conviction he was given a choice between what was called chemical castration to “cure” his homosexuality or jail. He chose to take the chemicals, but grew despondent and committed suicide in 1954. British Prime Minister Gordon Brown awarded Turing a posthumous apology for his “appalling” treatment in 2009. Turing was also given a royal pardon five years later.